Sauté onion and garlic in olive oil until translucent.
Set aside to cool.
Combine sausage, beef, breadcrumbs, cheese, eggs, parsley, salt , pepper and water (or broth) in a large bowl.
Mix well.
Roll into balls.
On a cookie sheet slightly greased or lined with parchment paper, bake meatballs at 375 degrees for about 15 minutes or until meatballs are browned. (Or cook meatballs on medium high in frying pan with a little oil until browned.)
Servings depend on how large you make the meatballs. (Approx. 16 medium sized meatballs.)